Weapons systems is an engineering discipline, dealing with designing and building weapons, that aims to find solutions to operational problems that arise in all aspects of battlefield management. The development and construction of an advanced weapon system, depends on diverse technological capabilities, and especially on the systematic thinking capabilities of its designers. Systems with the best performance capabilities are the ones that are compatible with the structure of the armed forces that employ them in the battlefield. While the decision to develop new weapons systems takes into account many considerations, the main one is often the cost of the system. This book presents the challenges that accompany the initiation, development and implementation of advanced weapons systems, as well as the main technologies required for building them.